1. Field of the Invention
The present invention generally relates to projection and display systems, and more particularly to a system for preparing documents for accessing and retrieving images stored on a separate medium.
2. Description of the Prior Art
The storage and retrieval of visual data has become increasingly important, as such information becomes more useful and necessary in modern business and technology. There are several conventional devices for handling image information, ranging from simple constructions such as slideshow carousels, to advanced electronic storage and display systems. Each of these devices, however, suffer from certain disadvantages due to the inherent limitations of either the storage medium, the access means, or the form of display.
For example, some media, like microfilm, require elaborate, bulky equipment to retrieve the data, although accessing the information is a simple matter once the microfilm is loaded onto the reader. Conversely, a slideshow carousel is extremely light and portable, but most of these devices limit access to sequential (forward or reverse) viewing in a predetermined order. Slideshow projectors also allow viewing by a larger audience, while microfilm readers are totally unsuited for this purpose. Computer graphic systems contain the same limitation, i.e, they provide only a single display on the user's CRT.
One apparatus having certain advantages of each of the foregoing systems is an overhead projector (OHP), used with transparencies. Transparencies allow for the random access of images as do microfilm and computer storage systems. Yet modern overhead projectors are much more compact than microfilm readers or computers having CRT displays. Actually, overhead projectors have recently been combined with computer graphics systems by the use of liquid crystal display (LCD) technology. A transmissive LCD panel, connected to and driven by a computer, may be placed on the stage area of an overhead projector, thereby projecting the same image on a screen that is also appearing on the computer's CRT.
The primary disadvantage of overhead projectors (with or without LCD panels) lies in the manipulation or control of the presentation of images. In a transparency/OHP system, for instance, fumbling, misalignment and mutilation of transparencies inevitably occurs during the presentation itself. An equally undesirable drawback in the alternative LCD/OHP system, is that access and retrieval of images is typically limited to sequential presentation, much like a slide projector. Although there are LCD/OHP systems which allow random access to stored images, these systems require additional interaction by the user, namely, typing in keyboard commands and file names.
It would, therefore, be desirable and advantageous to devise a system which is not so limited by the type of storage medium or display, but nevertheless has the advantages of each of the foregoing devices, particularly simplified, but sophisticated, control in the presentation of images. Such a system is described in co-pending U.S. Patent Application Ser. No. 455,834 filed Dec. 15, 1989. That system utilizes a novel image access document for controlling a computerized retrieval and display architecture. The present invention is directed to methods of, and structures for, preparing such image access documents.
As further background, it is understood that several conventional image retrieval methods employ documents which contain the image and related information. For example, microfilm information storage arrangements, such as that shown in U.S. Pat. No. 3,980,401 issued to R. Holliday, have recorded indicia for randomly retrieving information from microfilm members when the indicia are aligned with reference means on the microfilm reader. Another conventional technique for retrieving photographic images (negatives) involves the use of aperture cards, such as FILMSORT brand aperture cards sold by Minnesota Mining & Manufacturing Co. (3M), assignee of the present invention ("FILMSORT" is a trademark of 3M). Finally, several devices which provide interactive education/entertainment employ cards having visual images and related information, such as audio information or answers to questions printed on the cards. Three such devices are shown in U.S. Pat. Nos. 4,337,375 issued to A. Freeman; 4,425,099 issued to R. Naden; and 4,673,357 issued to T. Ito. None of the foregoing systems, however, utilize a card having a visual image printed thereon which corresponds to the same image stored on a separate medium.